1. Field of the Invention
The present invention relates to a magnetic recording and reproducing apparatus. More specifically, the present invention relates to a magnetic recording and reproducing apparatus for recording and reproducing information by scanning a running magnetic tape unreeled from a tape cassette, and a driving method thereof.
2. Description of the Related Art
In general, a magnetic recording and reproducing apparatus as shown in FIG. 1, includes a deck 10 for supporting a head drum 11 which scans a magnetic tape (not shown) that is running and thus, records or reads information on or from the magnetic tape, and a sub-deck 20 which is slidably installed on the deck 10 for movement in loading/unloading directions. The deck 10 includes a guide means for pulling the magnetic tape out of a tape cassette placed in reel tables 21 and 22 of the sub deck 20, and for guiding the tape to run (or travel) on a designated tape path via the head drum 11.
Typically, the guide means includes a tension pole 13a, a pair of pole base assemblies 14 and 15, a capstan shaft 16, a pinch roller 17a, and a review pole 18a. 
The tension pole 13a is supported by a tension arm 13 interlocked therewith by the sliding motion of the sub-deck 20, and adjusts the tension of a tape supplied from a feed reel (or a supply reel) of the tape cassette. For example, in play mode the tension pole 13a actively moves in correspondence to the tension of the running tape in order to adjust its tension. In stop mode, the tension arm 13 and the tension pole 13a are interlocked and move together by means of a cam gear that is rotated by the driving force of a drum motor 12, and the position of the tension pole 13a is controlled to release the tension of the tape.
The pole base assemblies 14 and 15 are interlocked with the drum motor-driven cam gear 19, and are movably installed in the loading/unloading directions. That is, during the tape loading process, the pole base assemblies 14 and 15 draw out the tape and guide a length of the tape to be wound around the head drum 11. During the tape unloading process, the pole base assemblies 14 and 15 return to their original position.
The capstan shaft 16 is driven by a capstan motor (not shown) installed in the deck 10. When the capstan shaft 16 rotates, the tape running between the pinch roller 17a and the capstan shaft 16 is guided. Here, the driving force from the capstan motor is transmitted to reel tables 21 and 22, respectively, for driving a tape reel of the tape cassette.
The pinch roller 17a is installed on a pinch arm 17 that is rotatably mounted to the deck 10. The pinch arm 17 rotates clockwise during the tape loading process, and as a result, the pinch roller 17a moves towards the capstan shaft 16. When the tape is running, the pinch arm 17 is compressed further in the clockwise direction to press the tape closely to the capstan shaft 16. The pinch arm 17 moves toward the capstan shaft 16 when the sub-deck 20 is loaded, and then returns to its original position during the unloading of the sub-deck 20 with the aid of a restoring force of a spring (not shown).
In addition, the deck 10 can further include a main sliding member (not shown) for controlling the motion of the pinch arm 17, and a compressing member (not shown) interlocked with the main sliding member. The main sliding member is also engaged with the cam gear 19, so that when the main sliding member slides back and forth, the compressing member and the pinch arm 17 all move together. The constitution of the main sliding member and the compressing member is a technique well-known to those skilled in the art and accordingly, a detailed description thereof is omitted for conciseness.
The review pole 18a is installed proximate to the pinch roller 17a to guide the running operation of the tape wound around a take-up reel of the tape cassette. The review pole 18a is supported by a review arm 18 that is rotatably installed in the deck 10. Similar to the pinch arm 17, the review arm 18 is typically interlocked with the sub-deck 20 or the main sliding member.
However, the conventional magnetic recording and reproducing apparatus with the above constitution has several problems. For example, it requires a large number of components for manufacture, and has a highly complicated structure. And these problems also resulted in large weight and high cost of manufacture. To overcome these problems, studies have been actively done to simplify the structure of the magnetic recording and reproducing apparatus by deleting as many unnecessary components as possible. For instance, the development of a new structure having only one deck with no sub-deck is one proposed improvement. Also, attempts have been made to delete some components of certain parts, such as the guide means, and thus simplify the structure of the guide means for guiding the tape or adjusting the tension of the tape.
Accordingly, a need exists for a system and method providing a simple structure for a magnetic recording and reproducing apparatus having fewer components, yet being able to control the tension of the tape and the driving of the pinch roller.